The prevalence of positional plagiocephaly/brachycephaly (PPB) increased dramatically following the Back to Sleep campaign, from 5% to approximately 20%-30%. It has been assumed that PPB is a benign side effect of supine sleep positioning and that skull deformation would resolve as children mature. However, several studies now challenge these assumptions. In a recently completed longitudinal study, we found that children with PPB were at elevated risk for developmental delays relative to unaffected controls from infancy through age 36 months. Although it is unclear whether PPB causes developmental delays, we hypothesize that PPB is a marker that could be used to identify infants in need of developmental assessment and intervention. Specifically, we anticipate that early and potentially subtle neuromotor deficits make infants vulnerable to developing PPB and predict deficits in other areas of development. This study will be the first long-term follow-up of children with and without PPB. We will re-assess children who participated in our earlier cohort study with PPB (n=215) and unaffected controls (n=163) at age 8 years. The study will explore two primary hypotheses: (1) Children with PPB will score lower than unaffected controls on neuropsychological and academic achievement measures, and (2) These differences are mediated by infant motor skills. We will also examine the demographic and clinical variables that predict development in children with PPB. Finally, we will examine whether differences in head shape remain measureable and observable for children with PPB versus unaffected controls.